1. The Field of the Invention
The invention relates to a molded part, in particular a decorative part and/or a trim part for the passenger compartment of a vehicle, and to an injection molding process and a compression molding process for producing molded parts, in particular decorative parts and/or trim parts for the passenger compartment of a vehicle.
2. Background and Relevant Art
Molded parts for a passenger compartment of a vehicle generally comprise a support of plastic, a decorative layer and a ductile insert of ductile material. The decorative layer may extend over the entire molded part, but it is similarly possible for it only to be assigned to a partial region of the molded part. The same applies to the ductile insert. It may extend at least to the greatest extent in or over the entire molded part, but it may also only be provided in a partial region of the molded part.
Such molded parts are fitted in the passenger compartment of a vehicle, in particular in areas in which the impact of a driver or passenger is to be expected in an accident. The insert is intended here to ensure the overall deformability of the molded part, i.e., as far as possible prevent it from rupturing or cracking on impact.
Such parts are known per se; a metal is used as the ductile insert, in particular an aluminum or steel sheet. However, these metals are relatively heavy and consequently contribute correspondingly to the overall weight of the vehicle; their properties also do not always meet the desired requirements with respect to strength and elasticity.
Various production processes are known for the production of decorative or trim parts for the passenger compartment of a vehicle which merely comprise a decorative layer (which however may have in addition to the actual decorative ply further structural and/or adhesive plies) and a support of plastic. According to a first variant, first the decorative layer is pressed into the desired form in a compression mold, so that it forms a decorative shell. Subsequently, the preformed decorative layer or the decorative shell is laminated with a film of plastic molding compound in an injection mold to form the support. According to a second variant, first the support is formed in an injection mold and subsequently the sheet-like material is pressed onto the support in a compression mold to form the decorative layer. Alternatively, according to a third variant, the preformed decorative shell is placed together with a plastic molding compound into a compression mold and the molded part is produced in it by means of pressing. According to a fourth variant, first the support is formed in a compression mold and subsequently the sheet-like material is pressed onto the support in a compression mold to form the decorative layer. These processes consequently already require in each case at least two separate process steps, which are carried out on different molds. Consequently, the processes are time-consuming and labor-intensive and are consequently correspondingly cost-intensive.
This applies all the more to processes developed on this basis for producing the molded parts mentioned at the beginning which additionally have a ductile insert of ductile material. This ductile insert must be additionally bonded or pressed onto the molded part.
According to a known process, the production of these molded parts is based on the aforementioned second variant. The difference is that, before the formation of the support in the injection mold, first the ductile material forming the insert is introduced into the cavity of the mold and positioned, and then, after closing the cavity, the plastic molding compound is applied to it by injection. In this first step, consequently, a composite unit comprising the plastic support and the insert of ductile material is created. Subsequently, as in the previously described second variant, the sheet-like material is pressed onto the support in a compression mold to form the decorative layer.